Few questions about injection in Gen VII

[Gamer2408]

After I install homebrew in the 3DS, where I can find a guide to inject pokemon (I prefer use this method over edit my file, but I'm not sure is this posible), I understand that to play a gen VII game is neccesary to update to the latest firmware for 3DS, but the 3DS with homebrew/Custom firmware this will not create a problem?  With the custom firmware I can create a backup of my gamefile to check in pkhex? and last after I inject something in the game, is there a problem to use the game in a unaltered 3DS? (Specifically a new 3DS)

[Liger0]

You just need homebrew, not the CFW. You can use the version you want and you don't need to update, because if you want to access the online you just need to use the app "ctrhttp" that's included in the starter kit. The VII generation saves are more easy to backup than the VI (Well, ORAS require particular things to do only if you are on 11.1+).

For Sun and Moon (whatever version of 3ds you own) you just need to put in your 3ds folder the program called JKSM. With that you can extract, modify the sav with Pkhex on PC and then restore it again with JKSM.

[Gamer2408]

So I only need to homebrew installed? in the start I thought this will be more difficult and need more time. 

Thanks for the answer.